Means for protecting the supply cables of mining machines



July 1955 R. L. J. MACRAE 3,192,704

MEANS FOR PROTECTING THE SUPPLY CABLES OF MINING MACHINES 4 Sheets-Sheet1 Filed March 1, 1962 FIG.3

y 6, 1.965 R. 1.. J. MACRAE 3,192,704

MEANS FOR PRQTECTING THE SUPPLY CABLES OF MINING MACHINES Filed March 1,1962 4 Sheets-Sheet 2 y 6, 1955 R. J. MACRAE 3,192,704

MEANS FOR PROTECTING THE- SUPPLY CABLES OF MINING MACHINES Filed March1, 1962 4 Sheets-Sheet a FIG. 5.

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y 1955 R. L. J. MACRAE 3,192,704

MEANS FOR PROTECTING THE SUPPLY CABLES OF MINING MACHINES I 7 FiledMarch 1, 1962 v v 4 Sheets-Shet 4 farm/45AM M w/P 4M fi'wlw 72% Amway:

United States Patent C) 3,192,794 MEANS FUR PRGTECTTNG THE SUFPLY CABLES0F MENHQG MACES Ronald L. 3. h iacrae, Ashhy-de-la-Zoueh, England,assignor to Coal Industry (Patents) Limited, London, England Filed Mar.1, N62, er. No. 176,693 4 Claims. ill. 59-78.!)

This invention relates to means for protecting a flexible cable leadingto a machine of the type which in operation travels to and fro over adefined path and is supplied with power (hydraulic, pneumatic orelectric) through flexible trailing cables connected at one end to themachme and at the other end' to a power supply. Such machines willhereinafter be referred to as of the type described. One example ofsucha machine is a mining machine arranged to traverse the face of acoal seam and in that case the cable may be a supply cable. It will beunderstood that the word cable includes hose.

It is a present practice where such mining machines are in use, to leadthe trailing cable to the mid point of the face, and to anchor it atthat point. From there, a length of cable equal to half the travel ofthe mining machine, is led to the said machine. As the mining travelsfrom one end of the face to the other, the flexible cable which, whenthe machine is at one end of its travel, is fully ex tended, is turnedback on itself to form a loop which is dragged along by the miningmachine until the machine reaches the other end of the face when thecable is once again fully extended. As the said machine moves in theopposite direction, a reverse loop is formed, and this is, in turn,dragged down the face. This system has the following disadvantages.

(i) The cable is under tension, due to the friction of its own weight,and is thus liable to suffer damage.

(ii) The cable is free to rub on itself and other surfaces,

and the outer cover can be severely abraded.

(iii) Unless an operator supervises the trailing loop, the latter isliable to be fouled and fractured by projections found on a mineralface.

An object of the present invention is to provide means for protecting aflexible cable of a machine of the type described, and, in accordancewith the present invention, this object is achieved by providing a chainfor carrying the flexible cable, the chain being so constructed that theflexible cable whilst being free to form a natural loop within itslength to follow movement of the machine, is not subjected to draggingtension, does not rub on itself or the floor, and is protected againstdamage arising through fouling of the loop. The chain links areconstructed and spaced in such a manner that when the chain is foldedback on itself to accommodate looping of the carried cable, the upperlength of chain can slide freely on the lower length.

A trough may be provided, adapted to accommodate the chain in its foldedcondition and arranged to extend over the full distance of travel of themachine; where the machine is a mining machine, the trough isconveniently provided on a face conveyer with which the mining machinein operation co-operates.

The chain may be connected to the machine by a first swivel attachmentadapted to permit the portion'of chain adjacent the machine to move froma position in which it extends in one direction relative to the machineto a position in which it extends in the opposite direction. The chainmay be connected towards one end of a second similar'swivel attachmentat a location intermediate the ends of the path of the machine; the saidsecond swivel attachment may be arranged for limited translationalmovement in' a direction parallel to the path of the machine and may beadapted to perform said translational movement when ice the machineapproaches one end of the said path, whereby the power supply to themachine is cut oil".

Two embodiments of the present invention will now be described ingreater detail, by way of example only, with reference to theaccompanying drawings of which FIGURE 1 shows a plan View, partlyin'section, of one form of chain,

FIGURE 2 shows a view of'one of the channel-shapedlinks in'the directionof arrow A in FIGURE 1,

FIGURE 3 is a cross-sectional view along line 33 o'f FIGURE 1, with anelectric cable and a water hose in position in the chain, 7

FIGURE 4 shows a vertical transverse section through a trough mounted ontheside of an armoured'fiexibleconveyor (part only of which is shown),the'trough accommodating two lengths of the chain shown in FIGURES 1-3,on'e'length of chain resting on the other,

FIGURE 5 shows schematically and in plan view a general arrangement of amining machine mounted for move ment along an armoured flexible conveyorand having a flexible trailing cable protected by the means of thepresent invention,

FIGURES 6, 7 and 8' show schematically and in side views variouspositions of the arrangement of FIGURE 5, parts only'of the arrangementbeing shown,

FIGURE 9 shows a plan view of a second form of nected togetheralternately with links 3 each constituted by a pair of parallel platessecured'to links 2 by riviets 4. The link 2 are channel-shaped in thedirection of the length of the chain 1 so that, as can be seen in FIGURE3, the electric supply cable 5 and, as shown, the water hose 6 'ofthe'rnining machine to which the chain 1 is to be attached, can be fullyinserted into the-longitudinal opening defined by the series of links 2.The cable 5 (and the water hose 6) is retained in the links 2 by theprovision in eachlink 20f a removable pin 7 which extendsacross theotherwise openside S of the link 2 opposite to the base 9to which the"adjacent links 3 are connected. It will be seen that each link 2comprises upper and lower vertically-spaced horizontal limbs 10interconnected by an upstanding pom tion' 9 to form a generallyU-sectioned link. As can be further seen from the drawing, portions 9 onadjacent? links are pivotally connected together for relative movementabout parallel and horizontal axes disposed trans verse" to the lengthof the chain; The limbs 10 are dis- Y posed all in the same direction todefine the longitudinal opening for the cable; The limbs 10 of eachlinkare each strengthened by an" integral longitudinal rib 11, whilstthe upstanding portion 9 is similarly strengthened by an integraltransverse rib 1 3which constitutes a continuation of the ribs 11. Topermit sliding of the chain on itself in a manner to be described below,it will beseen that each limb ltl of each'link 2 has a-length in thedirection of the chain, greater than the distance separatingadjacentlimbs it) on immediately adjacent links, and has opposed lateral V edgeportions lZ'inwardly turned towards the central axis of the chain.

The use of the above described chain will now be de'- scribed withreference to FIGURES 4-8.-

Fr-om FIGURE 5 will be seen the general arrangement of'a miningmachine'Zll (of which one end only is shown) which traverses the coalface (not indicated); on the armoured conveyor 21. The conveyor 21 (seeFIGURES 4 and'S) differs from the well-known armoured conveyors only inthat there is attached to the goat side of the conveyor and extendingalong its length a fabricated trough 22 (FIGURE 4) of such internaldimensions as to receive both lengths 23 and 24 of the chain 1 when itis folded upon itself. The mining machine 2% is supplied with powerthrough a flexible cable 5 having a first portion 5a leading from asource of supply (not shown) to a swivel (see below) located at themid-point of the conveyor 21 i.e. the mid-point of travel of the machine2-3, and a second portion 5b extending between the swivel 25 and themachine 20, the latter portion 5!; having a length equal to half thetravel of the machine 2%. The cable portion 512 is inserted into thechain so as to be effectively enclosed thereby on all sides except inthe vicinity of the longitudinal opening in the chain, where pins 7 areinserted at spaced intervals to prevent movement of the cables laterallyout of the chain.

In FIGURES 5-8, for the sake of clarity, only a part of cable portion 5bis shown as being enclosed in the links 23 of chain 1 but it will beunderstood that the whole length of cable portion 51) between themachine 28 and a swivel 25 is so enclosed. Similarly, in FIGURES 58 thewater hose 6 has also been omitted.

The chain 1 is connected at one end to the machine 29 by means of aswivel attachment 26 comprising a tubular elbow 27 to which the lastlink 3 of the chain I is directly connected at 28, which is rotatablymounted in a bearing block 29 secured on the machine 29.

The swivel 25 is similar to swivel attachment 26 and is mounted at themid-point of the traverse of the machine for limited sliding movement ina frame 3 The, mouth 32 of the tubular elbow 31 of swivel 25, throughwhich the cable 5 projects is arranged in line with the trough 22 andthe outer side wall of the trough 22 is cut-away at this point to permitthe elbow 31 to be pivoted into the oppositely facing position (seeFIGURES 7 and 8).

Mounted in the frame such as to project in the path of the swivelbearing block 33 is an electrical switch plunger 34 which operates tocut-off the supply of power to the haulage motor of the machine 2%,

The operation of the above described arrangement is as follows:

Assuming the machine is in the position shown in FIG- URE 5 and istraversing in the direction of arrow A, the chain 1 will be folded uponitself and the upper length 23 will slide over the lower length 24. Itis to be noted at this stage, that the spacing and construction of thelinks 2 (FIGURE 1) is such that the links 2 of the upper length 2 3 willslide freely on the links 2 of the lower length. Thus, the upper length23 of chain 1 can slide on the lower length 23 without engaging ordamaging the portion of the cable 5 in the lower length 2 The upperlength 23 continues to slide over the lower length 24 as the machine 28'traverses the face through the position of FIGURE 6 (in which a part ofthe upper length 23 is still moving over the lower length 24 and a partof the upper length 23 is clear of the lower length 24 and engagesdirectly in the trough 22 not shown in FIGURE 6) to the position inFIGURE 7 in which the machine 20 is approaching the right-hand end ofits traverse. In the position of FIGURE 7, the whole length of the chainIt now directly engages within the trough 22 and, after the elbow 31 ofswivel 25 has pivoted from a position in which it faces to the left (seeFIGURE 6) to a position in which it faces to the right (see FIGURE 7),the chain 1 lies in a straight line in the trough 22. It will be noticedalso that the bearing block 33 has been moved a short distance to theright from the position shown in FIGURE 6 by the machine 26 towing thechain 1, and that the upper surface of block 33 is about to engage (andthus depress) the switch plunger 34. Continued movement of the machine20 in the direction of arrow A (FIGURE 5) causes the plunger 34 to bedepressed by the block 33 thus operating its switch such as to stop themachine 20.

Even after the switch is operated by plunger 34, the machine 20 willcontinue for a short distance due to its inertia and delay in arrestingthe machine, so that by the time the machine 2%} actually stops, theblock 33 will have been drawn clear of the plunger 34 as shown in FIG-URE 8.

The installation is now ready for traverse of the machine 29 across theface in a direction opposite to that shown by arrow A in FIGURE S.Traverse of the machine Zil in this direction causes the above describedevents to occur but all in the opposite sense.

In FIGURES 9 and 10, and 11, of the accompanying drawings is shown asecond form of chain which can also be used in the manner describedabove. The chain shown in FIGURES 9 and 10 comprises channel-shapedlinks 42 each provided at one end with an apertured lug 43 and at theopposite end an apertured fork 44, the links 42 being pivotallyconnected together by rivets 48 each of which passes through theapertured lug 43 of one link 42 and the apertured fork 44 of theadjacent link 42. It is seen in FIGURE 10 that the strengtheningintegral rib 56 in this case presents an arcuate surface to the cable45. The cable &5 (and water hose 46) is retained in the links 42 by theprovision in every fifth link of a spring dowel pin 47. Furtherstrengthening of each link 42 is provided by the inturned portions 52which also serve to ensure that when the chain is folded on itself onelength can slide freely on the other length.

I claim:

1. Means for protecting a flexible supply cable arranged to connect asource of supply to a unit movable relative to said source of supply,comprising a chain adapted to receive and carry said flexible supplycable, said chain comprising a plurality of links each having a lowerhorizontal limb, an upper horizontal limb spaced above said lowerhorizontal limb and an upstanding portion interconnecting upper andlower limbs to form a generally U-sectioned link. said links beingarranged with their limbs direction all in the same direction towardsone side of the chain to define an opening longitudinally of the chain,into which opening said flexible supply cable can be frilly inserted,and means pivotally connecting adjacent links to each other for relativemovement about parallel and horizontal axes disposed transverse to thelength of the chain, each horizontal limb of a link having a length inthe direction of the chain, greater than the distance separatingimmediately adjacent limbs on adjacent links and further having opposedlateral edge portions disposed transverse to the length of the chain,which edge portions are inwardly turned towards the central aXis of thechain whereby when the chain is folded back on itself, an upper lengthof the said chain can slide freely on a lower length of the said chain.

2, Means for protecting a flexible supply cable arranged to interconnecta source of supply and a mining machine mounted for travel along anarmoured face conveyor, said source of supply being disposedintermediate the ends of the conveyor, comprising a chain adapted toreceive and carry said flexible supply cable and having one end attachedto a location immediately adjacent said source of supply and theopposite end attached to the mining machine, and a trough mounted on oneside of said conveyor and adapted to support said chain, the lattercomprising a plurality of links each having a lower horizontal limb, anupper horizontal limb spaced above said lower horizontal limb and anupstanding portion mterconnecting said upper and lower limbs to form agenerally U-sectioned link, said links being arranged with theirhorizontal limbs directed all in the same direction towards one side ofthe chain to define an opening extending longitudinally of the chain,into which opening the said flexible supply cable can be fully inserted,and means pivotally connecting adjacent links to each other for relativemovement about parallel and horizontal axes disposed to the length ofthe chain, each horizontal limb of a link having a length in thedirection of the chain,

- greater than the distance separating immediately adjacent limbs onadjacent links and further having opposed lateral edge portions disposedtransverse to the length of the chain, which edge portions are inwardlyturned towards the central axis of the chain whereby when the chain isfolded back on itself, an upper length of the said chain can slidefreely on a lower length of the said chain.

3. Means as claimed in claim 2, wherein the said end of the chainattached to a location immediately adjacent said source of supply, isconnected to a swivel attachment adapted to permit a portion of thechain adjacent the said location to move from a position in which saidportion extends in one direction relative to said location to a positionin which said portion extends in the opposite direction.

4. Means as claimed in claim 3, wherein said swivel 1 attachment isaranged for limited translational movement in a direction parallel tothe path of movement of 5 translational movement to co-operate withswitch means operative to stop further movement of the machine.

References Cited by the Examiner UNITED STATES PATENTS 10 2,864,90712/58 Waninger.

3,020,362 2/62 Waninger 59-78 FOREIGN PATENTS 14,773 6/ l 1 Denmark.

CHARLES W. LANHAM, Primary Examiner.

1. MEANS FOR PROTECTING A FLEXIBLE SUPPLY CABLE ARRANGED TO CONNECT ASOURCE OF SUPPLY TO A UNIT MOVABLE RELATIVE TO SAID SOURCE OF SUPPLY,COMPRISING A CHAIN ADAPTED TO RECEIVE AND CARRY SAID FLEXIBLE SUPPLYCABLE, SAID CHAIN COMPRISING A PLURALITY OF LINKS EACH HAVING A LOWERHORIZONTAL LIMB, AN UPPER HORIZONTAL LIMB SPACED ABOVE SAID LOWERHORIZONTAL LIMB AND AN UPSTANDING PORTION INTERCONNECTING SAID UPPER ANDLOWER LIMBS TO FORM A GENERALLY U-SECTIONED LINK, SAID LINKS BEINGARRANGED WITH THEIR LIMBS DIRECTION ALL IN THE SAME DIRECTION TOWARDSONE SIDE OF THE CHAIN TO DEFINE AN OPENING LONGITUDINALLY OF THE CHAIN,INTO WHICH OPENING SAID FLEXIBLE SUPPLY CABLE CAN BE FULLY INSERTED, ANDMEANS PIVOTALLY CONNECTING ADJACENT LINKS TO EACH OTHER FOR RELATIVEMOVEMENT ABOUT PARALLEL AND HORIZONTAL AXES DISPOSED TRANSVERSE TO THELENGTH OF THE CHAIN, EACH HORIZONTAL LIMB OF A LINK HAVING A LENGTH INTHE DIRECTION OF THE CHAIN, GREATER THAN THE DISTANCE SEPARATINGIMMEDIATELY ADJACENT LIMBS ON ADJACENT LINKS AND FURTHER HAVING OPPOSEDLATERAL EDGE PORTIONS DISPOSED TRANSVERSE TO THE LENGTH OF THE CHAIN,WHICH EDGE PORTIONS ARE INWARDLY TURNED TOWARDS THE CENTRAL AXIS OF THECHAIN WHEREBY WHEN THE CHAIN IS FOLDED BACK ON ITSELF, AN UPPER LENGTHOF THE SAID CHAIN CAN SLIDE FREELY ON A LOWER LENGTH OF THE SAID CHAIN.